The present invention relates generally to traffic lights, and more particularly to a novel bracket mechanism for partially supporting one or more traffic light units in spaced relation to vertical post means.
It is known to arrange traffic light assemblies in multiple groupings about central vertical post means. Typically, each traffic light assembly comprises a red stop light, a green "go" light, and a yellow caution light. The three lights of each assembly are arranged in vertical array. Each multiple group of lights is commonly located at a traffic intersection so that one set of lights faces each oncoming stream of vehicular traffic. In the case of a four-way traffic intersection, each traffic signal system will include four sets of traffic signals facing the four directions of oncoming traffic. Three-way traffic intersections and two-way intersections will have three sets of signals and two sets of signals, respectively. In each case, the individual traffic signal assemblies are equidistant from vertical post means, which may be suspended from an overhead cable or may extend upwardly from a vertical mast structure.
Under conventional practice, each traffic signal assembly is connected to the supporting post means via upper and lower cantilever arms. Typically, each cantilever arm includes a horizontal pipe threaded at its opposite ends, an internally threaded elbow connected to one end of the pipe, and a screw extending through a wall of the traffic signal assembly into the elbow. One end of each horizontal pipe is threadedly connected to the central post means, whereby each signal assembly is spaced from the post.
The post means commonly comprises a vertically elongated terminal box and a vertical pipe extending upwardly from the box. The upper horizontal pipes are connected to the upper end of the vertical pipe via a threaded connector, which may have therein one, two, three or four threaded openings, depending on the number of traffic light units in the system. The lower horizontal pipes are threaded into threaded openings in the terminal box. Electrical wiring for the traffic lights extends from the terminal box through the lower horizontal pipes and associated elbows up into the traffic light housings.
In some cases, the vehicular traffic signals are combined with pedestrian signals and/or vehicular turn signals. The light housing dimensions for such pedestrian signals and turn signals are smaller than corresponding dimensions for the stop-and-go vehicular signals. Therefore, when a particular installation has pedestrian signals or turn signals incorporated therein, it is necessary to use an additional vertical pipe connector between each smaller signal assembly and the associated upper horizontal support pipe. This somewhat complicates the installation process, and increases parts inventory requirements.
The present invention relates to a bracket mechanism which can be substituted for the upper horizontal pipes in the above-mentioned traffic light support system. A particular aim of the invention is to provide a bracket mechanism wherein one of the bracket arms is slidably adjustable on the central post means, whereby the bracket arm can be used either with the full height vehicular signals or with the shorter pedestrian signals or vehicle turn signals. Use of the slidably adjustable bracket arm eliminates the need for the above-mentioned additional vertical pipe connector. In one form, the invention comprises at least two horizontal bracket arms having the same lenth. One of the bracket arms has a downwardly extending socket or cap at one end for telescopement over the upper end of the supporting post means. The other bracket arm has a collar at one end for slidable encirclement of the post means below the socket (cap) on the first bracket arm. The collar on this second bracket arm is downwardly offset from the longitudinal axis of the second arm, whereby both arms can be disposed in a common horizontal plane passing through the upper end of the central post means. With the described bracket arm arrangement, it is possible to support a multiplicity of standard height vehicular stop-and-go light assemblies or various combinations of standard height assemblies and reduced height light assemblies.